Alternate Skill Mechanics
by Håvard
Dragon Magazine #165 included the article "Can You Juggle, Can You Swim? At the Same Time?"
This article introduced a skill system for Classic D&D using a roll below % based mechanic. Lately I have been toying with a similar system, though it is somewhat different from what was described in that article. One thing I changed was to add a % bonus based on level ranges, derived from what boxed set the character belongs to. This system can be used with my alternate skill list here or with the standard Gazetteer/RC skills or any other list.
Basic Mechanics
When you are attempting any non-combat action, roll d% below a number.
Unskilled (Ability Check): Roll below Ability Score +10%
Skilled
If you possess a relevant skill, roll d% below your Ability Score and add a bonus from the following chart:
| LEVEL RANGE | % Bonus | d20 Bonus |
| 1st-3rd level | +30% | +6 |
| 4-14th level | + 50% | +10 |
| 15-25th level | +60% | +12 |
| 26th+36th level | +70% | +14 |
The system above should replace all ability scores and general skill checks.
Optional Rule: Expertise
The DM may allow for characters to add 1 additional skill slot into a selected skill to gain expertise in that skill. This allows the character to add double his ability score to the number he has to roll below on d%.
Example: Bob the 1st level Dwarf buys the Athletics skill and adds an additional skill slot. He then adds double his strenght (2x18)32 + 30% = 62%. At 26th level, his chance of success will be 102%.
Optional Rule: Thief Skills
Using these optional added rules, the mechanics above can also be used to simulate Thief Skills. This will change the probabilities of success for Thief Skills quite a bit, but how much does that really matter? An added benefit is that this also allows for other characters to select Thief Skills as General Skills. Taking this one step further, I am toying with the following revised list for Thief Skills:
Revised Thief Skills
| New Thief Skill | Replaces | Notes |
| Sleight of Hands (Dex) | Pick Pockets, Escape | |
| Perception (Wis) | Find Traps, Hear Noise | |
| Athletics (Strength) | Climb Walls | |
| Stealth (Dex) | Hide In Shadows, Move Silently | |
| Acrobatics (Dex) | Previously a General Skill | |
| Devices (Dex) | Remove Traps, Pick Locks | |
| Read Languages (4th Level) (Int) | Read Languages | The only change is chance of success. Available at 4th Level |
Other Thief abilities such as Backstab and Use Scrolls are not affected by this change.
These changes mean that Thieves go from 8 to 6 skills at 1st level. Other characters are also allowed to select these skills by spending General Skill slots. To compensate for this I add the following benefits to the Thief Class:
- Thieves are allowed to select two additional skills from the Special Skill List.
- Thieves may choose to forego one or more Thief Skill replacing them with any other General Skill (not including Special Skills).*
*=Borrowing this one from 5E.